1. Field of the Invention
The present invention relates to a light source of a non-self light emission type display device, and more particularly to a liquid crystal display device having a backlight using a light-emitting device as a light source.
2. Description of the Related Art
Recently, a liquid crystal display device is widely used as a display device. In particular, the liquid crystal display device is of a thin type having a small thickness with light weight and low power consumption, and thus is used as a display unit of a mobile apparatus.
However, since the liquid crystal display is not of the self light emission type, light irradiation means is required. In general, as the light irradiation device used in the liquid crystal display device, a planar light irradiation device called a backlight is widely used. Conventionally, a cold cathode discharge tube is used in a light-emitting device (also referred to as a light source) of a backlight. However, recently, a light-emitting diode (hereinafter, referred to as LED) is also used as the light-emitting device of a mobile apparatus.
Japanese Laid-Open Patent Publication No. Sho. 64-88426 discloses a liquid crystal display device using a LED as a light source. Japanese Laid-Open Patent Publication No. 2002-162626A describes a technology relating to heat radiation of an LED.